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<h1 class="topictitle1">parallel_invoke Template Function</h1>

  
<div>
 <div class="section"><h2 class="sectiontitle">Summary</h2> Template function that evaluates several functions in parallel. </div>

 <div class="section"><h2 class="sectiontitle">Header</h2> 
<pre>#include "tbb/parallel_invoke.h"</pre>
 </div>

 <div class="section"><h2 class="sectiontitle">Syntax</h2> 
<pre>template&lt;typename Func0, typename Func1&gt;
void parallel_invoke(const Func0&amp; f0, const Func1&amp; f1);

template&lt;typename Func0, typename Func1, typename Func2&gt;
void parallel_invoke(const Func0&amp; f0, const Func1&amp; f1, const Func2&amp; f2);
template&lt;typename Func0, typename Func1, ..., typename Func9&gt;
void parallel_invoke(const Func0&amp; f0, const Func1&amp; f1, ..., const Func9&amp; f9);
</pre><div class="Note"><h3 class="NoteTipHead">
					Note</h3><p>When support for C++11 rvalue references become prevalent, the formal parameters may change to rvalue references.</p>
</div></div>

 <div class="section"><h2 class="sectiontitle">Description</h2> <p>The expression parallel_invoke(f<sub>0</sub>,f<sub>1</sub>,...,f<sub>k</sub>) evaluates
     f<sub>0</sub>(), f<sub>1</sub>(), ..., f<sub>k</sub>() possibly in parallel. There can be from 2
    to 10 arguments. Each argument must have a type for which <samp class="codeph">operator()</samp> is
    defined. Typically the arguments are either function objects or pointers to functions. Return
    values are ignored.</p>
</div>

  <div class="section"><h2 class="sectiontitle">Example</h2> <p>The following example evaluates <samp class="codeph">f(), g(),</samp> and
     <samp class="codeph">h()</samp> in parallel. Notice how <samp class="codeph">g</samp> and <samp class="codeph">h</samp> are
    function objects that can hold local state.</p>
<pre>#include "tbb/parallel_invoke.h"

using namespace tbb;

void f();
extern void bar(int);

class MyFunctor {
    int arg;
public:
    MyFunctor(int a) : arg(a) {}
    void operator()() const {bar(arg);}
};

void RunFunctionsInParallel() {
    MyFunctor g(2);
    MyFunctor h(3);
    tbb::parallel_invoke(f, g, h );
}
  </pre>
  </div>

  <div class="section"><h2 class="sectiontitle">Example with Lambda Expressions</h2> <p>Here is the previous example rewritten with C++11 lambda expressions, which generate function objects.</p>
<pre>#include "tbb/parallel_invoke.h"

using namespace tbb;

void f();
extern void bar(int);

void RunFunctionsInParallel() {
    tbb::parallel_invoke(f, []{bar(2);}, []{bar(3);} );
}
  </pre>
  </div>

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